package com.cmge.ad.spider.pipeline;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class JdbcUtils {
	//数据库用户名
	private static final String USERNAME = "root";
	//数据库密码
	private static final String PASSWORD = "";
	//驱动信息 
	private static final String DRIVER = "com.mysql.jdbc.Driver";
	//数据库地址
	private static final String URL = "jdbc:mysql://localhost:3306/qu_le?useUnicode=true&characterEncoding=UTF-8";
	private static Connection connection;
	private static PreparedStatement pstmt;
	private ResultSet resultSet;
	
	/**
	 * 获得数据库的连接
	 * @return
	 */
	public static Connection getConnection(){
		try {
			Class.forName(DRIVER);
			if(connection == null){
				connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
				System.out.println("获取连接成功！");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return connection;
	}

	
	/**
	 * 增加、删除、改
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public static boolean updateByPreparedStatement(String sql, List<Object>params)throws SQLException{
		boolean flag = false;
		int result = -1;
		PreparedStatement pstmt = connection.prepareStatement(sql);
		int index = 1;
		if(params != null && !params.isEmpty()){
			for(int i=0; i<params.size(); i++){
				pstmt.setObject(index++, params.get(i));
			}
		}
		result = pstmt.executeUpdate();
		flag = result > 0 ? true : false;
		
		pstmt.close();
		return flag;
	}

	/**
	 * 查询单条记录
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public static Map<String, Object> findSimpleResult(String sql, List<Object> params) throws SQLException{
		Map<String, Object> map = new HashMap<String, Object>();
		int index  = 1;
		pstmt = connection.prepareStatement(sql);
		if(params != null && !params.isEmpty()){
			for(int i=0; i<params.size(); i++){
				pstmt.setObject(index++, params.get(i));
			}
		}
		ResultSet resultSet = pstmt.executeQuery();//返回查询结果
		ResultSetMetaData metaData = resultSet.getMetaData();
		int col_len = metaData.getColumnCount();
		while(resultSet.next()){
			for(int i=0; i<col_len; i++ ){
				String cols_name = metaData.getColumnName(i+1);
				Object cols_value = resultSet.getObject(cols_name);
				if(cols_value == null){
					cols_value = "";
				}
				map.put(cols_name, cols_value);
			}
		}
		
		resultSet.close();
		pstmt.close();
		return map;
	}

	/**查询多条记录
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public static List<Map<String, Object>> findModeResult(String sql, List<Object> params) throws SQLException{
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		int index = 1;
		PreparedStatement pstmt = connection.prepareStatement(sql);
		if(params != null && !params.isEmpty()){
			for(int i = 0; i<params.size(); i++){
				pstmt.setObject(index++, params.get(i));
			}
		}
		ResultSet resultSet = pstmt.executeQuery();
		ResultSetMetaData metaData = resultSet.getMetaData();
		int cols_len = metaData.getColumnCount();
		while(resultSet.next()){
			Map<String, Object> map = new HashMap<String, Object>();
			for(int i=0; i<cols_len; i++){
				String cols_name = metaData.getColumnName(i+1);
				Object cols_value = resultSet.getObject(cols_name);
				if(cols_value == null){
					cols_value = "";
				}
				map.put(cols_name, cols_value);
			}
			list.add(map);
		}

		resultSet.close();
		pstmt.close();
		return list;
	}

	/**通过反射机制查询单条记录
	 * @param sql
	 * @param params
	 * @param cls
	 * @return
	 * @throws Exception
	 */
	public <T> T findSimpleRefResult(String sql, List<Object> params,
			Class<T> cls )throws Exception{
		T resultObject = null;
		int index = 1;
		pstmt = connection.prepareStatement(sql);
		if(params != null && !params.isEmpty()){
			for(int i = 0; i<params.size(); i++){
				pstmt.setObject(index++, params.get(i));
			}
		}
		resultSet = pstmt.executeQuery();
		ResultSetMetaData metaData  = resultSet.getMetaData();
		int cols_len = metaData.getColumnCount();
		while(resultSet.next()){
			//通过反射机制创建一个实例
			resultObject = cls.newInstance();
			for(int i = 0; i<cols_len; i++){
				String cols_name = metaData.getColumnName(i+1);
				Object cols_value = resultSet.getObject(cols_name);
				if(cols_value == null){
					cols_value = "";
				}
				Field field = cls.getDeclaredField(cols_name);
				field.setAccessible(true); //打开javabean的访问权限
				field.set(resultObject, cols_value);
			}
		}
		return resultObject;

	}

	/**通过反射机制查询多条记录
	 * @param sql 
	 * @param params
	 * @param cls
	 * @return
	 * @throws Exception
	 */
	public <T> List<T> findMoreRefResult(String sql, List<Object> params,
			Class<T> cls )throws Exception {
		List<T> list = new ArrayList<T>();
		int index = 1;
		pstmt = connection.prepareStatement(sql);
		if(params != null && !params.isEmpty()){
			for(int i = 0; i<params.size(); i++){
				pstmt.setObject(index++, params.get(i));
			}
		}
		resultSet = pstmt.executeQuery();
		ResultSetMetaData metaData  = resultSet.getMetaData();
		int cols_len = metaData.getColumnCount();
		while(resultSet.next()){
			//通过反射机制创建一个实例
			T resultObject = cls.newInstance();
			for(int i = 0; i<cols_len; i++){
				String cols_name = metaData.getColumnName(i+1);
				Object cols_value = resultSet.getObject(cols_name);
				if(cols_value == null){
					cols_value = "";
				}
				Field field = cls.getDeclaredField(cols_name);
				field.setAccessible(true); //打开javabean的访问权限
				field.set(resultObject, cols_value);
			}
			list.add(resultObject);
		}
		return list;
	}

	/**
	 * 释放数据库连接
	 */
	public void releaseConn(){
		if(resultSet != null){
			try{
				resultSet.close();
			}catch(SQLException e){
				e.printStackTrace();
			}
		}
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) throws SQLException {
		JdbcUtils jdbcUtils = new JdbcUtils();
		jdbcUtils.getConnection();

		/*******************增*********************/
		/*		String sql = "insert into userinfo (username, pswd) values (?, ?), (?, ?), (?, ?)";
		List<Object> params = new ArrayList<Object>();
		params.add("小明");
		params.add("123xiaoming");
		params.add("张三");
		params.add("zhangsan");
		params.add("李四");
		params.add("lisi000");
		try {
			boolean flag = jdbcUtils.updateByPreparedStatement(sql, params);
			System.out.println(flag);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}*/


		/*******************删*********************/
		//删除名字为张三的记录
		/*		String sql = "delete from userinfo where username = ?";
		List<Object> params = new ArrayList<Object>();
		params.add("小明");
		boolean flag = jdbcUtils.updateByPreparedStatement(sql, params);*/

		/*******************改*********************/
		//将名字为李四的密码改了
		/*		String sql = "update userinfo set pswd = ? where username = ? ";
		List<Object> params = new ArrayList<Object>();
		params.add("lisi88888");
		params.add("李四");
		boolean flag = jdbcUtils.updateByPreparedStatement(sql, params);
		System.out.println(flag);*/

		/*******************查*********************/
		//不利用反射查询多个记录
		/*		String sql2 = "select * from userinfo ";
		List<Map<String, Object>> list = jdbcUtils.findModeResult(sql2, null);
		System.out.println(list);*/

		//利用反射查询 单条记录
//		String sql = "select * from userinfo where username = ? ";
//		List<Object> params = new ArrayList<Object>();
//		params.add("李四");
//		try {
//			userInfo = jdbcUtils.findSimpleRefResult(sql, params, UserInfo.class);
//			System.out.print(userInfo);
//		} catch (Exception e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		}
	}

}
